kilogram (kg)

The kilogram (kg) is the base unit of mass in the SI system of units. The standard kilogram is a 1 kg corrosion resistant platinum/iridium cylinder, carefully preserved in the ...

objekt fluturues i paidentifikueshëm (UFO)

航空航天; 太空飞行

UFOs are unidentified aircraft which are attributed to alien space flight. One supposed UFO halted air traffic at Hangzhou Airport, China, on July 7. The appearance is being ...

anije kozmike

航空航天; 太空飞行

A reusable spacecraft with wings developed by the U.S. National Aeronautics and Space Administration (NASA) for human spaceflight missions. The first test flight took place in ...

zenit

航空航天; 太空飞行

The point on the celestial sphere directly above the observer. Opposite the nadir.

zeta (Z)

航空航天; 太空飞行

A multiplier, x1021 from the last letter of the Latin alphabet. See the entry for CGPM.

rreze x

航空航天; 太空飞行

Electromagnetic radiation in the neighborhood of 100 picometer wavelength.

peshë

航空航天; 太空飞行

The gravitational force exerted on an object of a certain mass. The weight of mass m is mg Newtons, where g is the local acceleration due to a body's gravity.